infinite-loop-direct.ll
3.44 KB
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; RUN: opt -S -gvn-hoist < %s | FileCheck %s
; Checking gvn-hoist in case of infinite loops and irreducible control flow.
; Check that bitcast is not hoisted beacuse down safety is not guaranteed.
; CHECK-LABEL: @bazv1
; CHECK: if.then.i:
; CHECK: bitcast
; CHECK-NEXT: load
; CHECK: if.then4.i:
; CHECK: bitcast
; CHECK-NEXT: load
%class.bar = type { i8*, %class.base* }
%class.base = type { i32 (...)** }
; Function Attrs: noreturn nounwind uwtable
define void @bazv1() local_unnamed_addr {
entry:
%agg.tmp = alloca %class.bar, align 8
%x.sroa.2.0..sroa_idx2 = getelementptr inbounds %class.bar, %class.bar* %agg.tmp, i64 0, i32 1
store %class.base* null, %class.base** %x.sroa.2.0..sroa_idx2, align 8
call void @_Z3foo3bar(%class.bar* nonnull %agg.tmp)
%0 = load %class.base*, %class.base** %x.sroa.2.0..sroa_idx2, align 8
%1 = bitcast %class.bar* %agg.tmp to %class.base*
%cmp.i = icmp eq %class.base* %0, %1
br i1 %cmp.i, label %if.then.i, label %if.else.i
if.then.i: ; preds = %entry
%2 = bitcast %class.base* %0 to void (%class.base*)***
%vtable.i = load void (%class.base*)**, void (%class.base*)*** %2, align 8
%vfn.i = getelementptr inbounds void (%class.base*)*, void (%class.base*)** %vtable.i, i64 2
%3 = load void (%class.base*)*, void (%class.base*)** %vfn.i, align 8
call void %3(%class.base* %0)
br label %while.cond.preheader
if.else.i: ; preds = %entry
%tobool.i = icmp eq %class.base* %0, null
br i1 %tobool.i, label %while.cond.preheader, label %if.then4.i
if.then4.i: ; preds = %if.else.i
%4 = bitcast %class.base* %0 to void (%class.base*)***
%vtable6.i = load void (%class.base*)**, void (%class.base*)*** %4, align 8
%vfn7.i = getelementptr inbounds void (%class.base*)*, void (%class.base*)** %vtable6.i, i64 3
%5 = load void (%class.base*)*, void (%class.base*)** %vfn7.i, align 8
call void %5(%class.base* nonnull %0)
br label %while.cond.preheader
while.cond.preheader: ; preds = %if.then.i, %if.else.i, %if.then4.i
br label %while.cond
while.cond: ; preds = %while.cond.preheader, %while.cond
%call = call i32 @sleep(i32 10)
br label %while.cond
}
declare void @_Z3foo3bar(%class.bar*) local_unnamed_addr
declare i32 @sleep(i32) local_unnamed_addr
; Check that the load is hoisted even if it is inside an irreducible control flow
; because the load is anticipable on all paths.
; CHECK-LABEL: @bazv
; CHECK: bb2:
; CHECK-NOT: load
; CHECK-NOT: bitcast
define void @bazv() {
entry:
%agg.tmp = alloca %class.bar, align 8
%x= getelementptr inbounds %class.bar, %class.bar* %agg.tmp, i64 0, i32 1
%0 = load %class.base*, %class.base** %x, align 8
%1 = bitcast %class.bar* %agg.tmp to %class.base*
%cmp.i = icmp eq %class.base* %0, %1
br i1 %cmp.i, label %bb1, label %bb4
bb1:
%b1 = bitcast %class.base* %0 to void (%class.base*)***
%i = load void (%class.base*)**, void (%class.base*)*** %b1, align 8
%vfn.i = getelementptr inbounds void (%class.base*)*, void (%class.base*)** %i, i64 2
%cmp.j = icmp eq %class.base* %0, %1
br i1 %cmp.j, label %bb2, label %bb3
bb2:
%l1 = load void (%class.base*)*, void (%class.base*)** %vfn.i, align 8
br label %bb3
bb3:
%l2 = load void (%class.base*)*, void (%class.base*)** %vfn.i, align 8
br label %bb2
bb4:
%b2 = bitcast %class.base* %0 to void (%class.base*)***
ret void
}